1. Impacts of Climate Change on Coastal Aquaculture in Bangladesh:
Socioeconomic and Ecological Perspectives
Nesar Ahmed & Marion Glaser
Social-Ecological Systems Analysis
Leibniz Center for Tropical Marine Ecology (ZMT), Bremen 28359, Germany
Project overview
The coastal aquaculture sector in Bangladesh is dominated by export-oriented freshwater prawn and saltwater shrimp farming, both are commercially known as “white gold” because of export value. However, prawn and shrimp culture in coastal Bangladesh has been accompanied by recent concerns over climate change. Different climatic variables including cyclones, drought, coastal flooding, rainfall, salinity, sea-level rise (SLR), and sea surface temperature (SST) have had adverse effects on coastal aquaculture. There is also overwhelming evidence that changes in theses climatic variables have detrimental effects on prawn and shrimp farms, and thus, severe effects on survival, growth, and production of prawn and shrimp. Considering extreme vulnerability to the effects of climate change on coastal aquaculture, community based adaptation (CBA) strategies and integrated coastal zone management (ICZM) are needed to cope with the challenges.
Climate change
Bangladesh is one of the most disaster-prone countries in the world because of its unique geographical location (Fig. 1). According to the GCRI (2015), Bangladesh is ranked 6th among countries vulnerable to climate change, while it was ranked 1st in Bangladesh is subject to seasonal changes in climatic conditions. The increasing risk from a combination of climatic variables, including: (1) cyclones, (2) drought, (3) coastal flooding, (4) rainfall, (5) salinity, (6) SLR, and (7) SST (Fig. 2).
Fig. 2. Climatic threats to Bangladesh
Fig. 1. Geographical location of Bangladesh with coastal aquaculture area
Food & nutrition
Rice
Prawn
Fish
Prawn-fish-rice farming
Shrimp-fish- rice farming
Shrimp
Export earnings
Agrarian change
Livelihood opportunities
Poverty alleviation
Coastal aquaculture
As part of agricultural development in coastal Bangladesh, prawn and shrimp farming were initiated in the 1970s and began to expand rapidly in the 1980s. Over the last three decades, prawn and shrimp culture have undergone a revolutionary development in coastal Bangladesh. Thousands of farmers have converted their low-lying rice fields to prawn and shrimp farms. The practice of prawn and shrimp farming with fish in rice fields, combined with high prices for prawn and shrimp in the international market, and rice and fish for household consumption and local market (Fig. 3), has led to an increasing production (Fig. 4).
Fig. 4. Coastal aquaculture production significantly
increased over the last decade
Fig. 3. Social and economic benefits from coastal aquaculture
Impacts
Climate change has been identified as threats to coastal aquaculture (Fig. 5). Cyclones has devastating effects on prawn and shrimp production. Drought is one of the foremost environmental limits to coastal aquaculture. Farmers loss their total harvest due to flood. Rainfall variation can also cause havoc on coastal aquaculture due to increase the risk of flood and drought. Increased salinity and temperature affects production of prawn and shrimp. SLR is likely to have dramatic effects on coastal aquaculture. Severe effects of climate change on coastal aquaculture would affect export earnings as well as economic growth (Fig. 6). + –
+ v
Climate
change
Tropical cyclones
SLR & SST
Salt water intrusion
Rainfall
Flood & Drought
Coastal aquaculture
Yield
Export earnings
Livelihood of poor
Economic growth
Income of farmers
Poverty and vulnerability
SST
Cyclone
Coastal aquaculture
Rainfall
Drought
Salinity
Flood
SLR
Climate change
Fig. 6. Effects of climate change on the economy
Fig. 5. Impacts of climate change on coastal aquaculture
Adaptation strategies
Community Based Adaptation (CBA): construction of dams, higher dikes, fencing and netting around farms, irrigation facilities, saltwater fish culture, introduce salt-tolerant and drought-resistant rice varieties, social forestry
Integrated Coastal Zone Management (ICZM): coastal embankment, afforestation, mangrove plantation, coastal rivers and estuaries management, cyclone shelters
Further Information
Ahmed, N Linking prawn and shrimp farming towards a green economy in Bangladesh: confronting climate change. Ocean and Coastal Management, 75: 33–42.
Ahmed, N., A. Occhipinti-Ambrogi, J.F. Muir The impact of climate change on prawn postlarvae fishing in coastal Bangladesh: socioeconomic and ecological perspectives. Marine Policy, 39: 224–233.
Ahmed, N., S.W. Bunting, S. Rahman, C.J. Garforth Community- based climate change adaptation strategies for integrated prawn-fish- rice farming in Bangladesh to promote social-ecological resilience. Reviews in Aquaculture, 6: 20–35.
Conclusions
Institutional support and collaboration among stakeholders, including community members, NGOs, government agencies, and community based organizations may help capacity development to implement CBA strategies
Coordination and collaboration among government organizations, NGOs, community based organizations, and local communities are essential for implementing ICZM